Henock 72:13-14 (from the Ethiopian text, numbering by R.H Charles)
13. And it returns to the east and enters into the sixth portal, and rises and sets in the sixth portal one-and-thirty mornings on account of its sign. 14. On that day, [the 31st of the 3rd month], the day becomes longer than the night, and the day becomes double the night, and the day becomes twelve parts, and the night is shortened and becomes six parts.
[3rd month: sunrises & sunsets on the 6th gate (sunrise moving north from east) ; it is composed of 31 days ; day = 12 parts & night = 6 parts (16 hours of daylight) ; day doubles the night]